Initial commit: terminal file browser & markdown viewer

A beautiful TUI for browsing files and reading markdown/code:
- Two-pane layout with file tree and content viewer
- Markdown rendering via Glamour
- Syntax highlighting via Chroma
- Auto-detects light/dark terminal theme
- Arrow key navigation, Esc to go back
- Page Up/Down, Home/End for scrolling

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

main.go

@@ -0,0 +1,114 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+const version = "0.1.0"
+
+func main() {
+	// Parse command line arguments
+	rootPath := "."
+	themeOverride := ""
+
+	for i := 1; i < len(os.Args); i++ {
+		arg := os.Args[i]
+		switch {
+		case arg == "-h" || arg == "--help":
+			printHelp()
+			os.Exit(0)
+		case arg == "-v" || arg == "--version":
+			fmt.Printf("reader v%s\n", version)
+			os.Exit(0)
+		case arg == "--light":
+			themeOverride = "light"
+		case arg == "--dark":
+			themeOverride = "dark"
+		case strings.HasPrefix(arg, "--theme="):
+			themeOverride = strings.TrimPrefix(arg, "--theme=")
+		case arg == "--save-theme":
+			// Save current detected theme
+			theme := DetectTheme()
+			if err := SaveThemePreference(theme.Name); err != nil {
+				fmt.Fprintf(os.Stderr, "Error saving theme: %v\n", err)
+				os.Exit(1)
+			}
+			fmt.Printf("Saved theme preference: %s\n", theme.Name)
+			os.Exit(0)
+		case !strings.HasPrefix(arg, "-"):
+			rootPath = arg
+		}
+	}
+
+	// Detect or set theme
+	var theme Theme
+	switch themeOverride {
+	case "light":
+		theme = LightTheme
+	case "dark":
+		theme = DarkTheme
+	default:
+		theme = DetectTheme()
+	}
+	SetTheme(theme)
+
+	// Verify path exists
+	info, err := os.Stat(rootPath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	// If it's a file, use its parent directory
+	if !info.IsDir() {
+		rootPath = "."
+	}
+
+	// Create and run the program
+	p := tea.NewProgram(
+		NewModel(rootPath),
+		tea.WithAltScreen(),
+		tea.WithMouseCellMotion(),
+	)
+
+	if _, err := p.Run(); err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func printHelp() {
+	help := `reader - A beautiful terminal file browser & markdown viewer
+
+Usage:
+  reader [path]     Open at path (default: current directory)
+  reader --light    Force light theme
+  reader --dark     Force dark theme
+  reader --save-theme  Save detected theme as default
+
+Options:
+  -h, --help       Show this help
+  -v, --version    Show version
+  --light          Use light theme
+  --dark           Use dark theme
+  --save-theme     Detect and save theme preference
+
+Keys:
+  ↑/↓              Navigate / scroll
+  Enter            Open file or folder
+  ←/→              Collapse/expand folders
+  Esc              Back to file browser
+  ?                Show help
+  q                Quit
+
+Theme is auto-detected from your terminal. Override with flags
+or save a preference with --save-theme.
+
+Config: ~/.config/reader/theme`
+
+	fmt.Println(help)
+}